The most operations needed are standard operations such as rotating,
sorting and clipping data. Those standard functions are already implemented
in the toolbox. To mark all programs of the graph toolbox, the program
names always begin with `gr_`. To make the tools usable, all tools should
lie within the path.

`gr_copy`- This is the identical mapping of the point sets.
It's possible to spcify sets, that must not be printed.
(for further informtionn see chapter: Standard Parameters)
`gr_analyze`- Checks the number of sets, the number of points per set,
the dimension of the points, the data value range.
`gr_analyze`can be used as a fast way of examining the data. `gr_transform`- Performs all possible transformations such as
translations, rotations, reflection, shearing and
perspective. Either each translation or scaling factor
is specified or a matrix is given (in an extra file or
as a first set) to define the view.
`gr_rotate`- Rotations of the points. A center of rotation can be specified.
`gr_scale`- This program scales the data set. It is possible to
specify a range for one coordinate. The sets will be
scaled to the given size, keeping the same ratio.
`gr_sort`- sorts the points in the set. The set can be sorted
upwards or downwards, using any coordinate for
comparison.
`gr_spline`- Cubic spline using the point data as control points. The
knots can be specified in an extra file or the
distribution of the knots can be specified (equal
distance distribution, arclength distribution, delta x
distribution).
`gr_curvature`- calculates the curvature of a polygon.
`gr_reduce`- Removing points from the set printing only every 2nd
point (2 is the default, but any other number can be
specified).
`gr_plane`- printing only the x or y or any specified
coordinate plane. More than one plane can be specified
and the order of the coordinates will be given by
the user.
`gr_merge`- removing the set separators.
`gr_split`- Splitting a set into two halfs or after a certain number
of points. (Works as an opposite of
`gr_merge`.) `gr_del_double`- Deletes points that are equal or within a specified epsilon
neighborhood. Only points that are neighboured in the file are
tested.
`gr_del_point`- Delete all points that lay within an interval or an epsilon box.
`gr_del_empty_sets`- All the empty sets will be removed.
`gr_invert`- inverts the order of the points in the set.
`gr_roll`- rolls the coordinats in clockwise direction: For a 3D
data set, that would mean, the old x-coordinate becomes
the new y-coordinate, while the old y-coordinate will be
printed out as new z coordinate and the old z value will
become the new x-value.
`gr_bspline`- Use the input points as control polygon for a bspline.
`gr_nurbs`- Use the input points as control polygon for Non Uniform
Rational BSplines (nurbs)
`gr_lift`- calculates the volume of curves. If it is used for more
than one set, the volume of every second curve is
subtracted from the volume of the first curves.
`gr_merge`- adjacent This routine tries to fit different sets with the same
start and endpoints together to a set.
`gr_trig`- calculates a Delaunay-triangulation out of a set of
points.
`gr_border`- the border of a structured set will be taken. The first
and last set will be printed and the first and last point
of any other set.
`gr_interior`- the interior of a structured set will be taken. The interior
of a structured set is defined as everything but the points
printed by
`gr_border`. `gr_uv2vu`- changing the orientation of a number of structured sets.
All input points must have the same number of points.
The output will have as many sets as the number of points
per set of the input data. Each set of the output data
will have as many point as the number of sets from the
input data.

For more detailed information on the modules see the `-h` online help on
each `gr_` tool.

Wed Jun 12 20:34:13 MET DST 1996